Battery pack

ABSTRACT

A battery pack includes a plurality of battery modules, each battery module having a plurality of stacked battery cells and a casing member surrounding the plurality of battery cells, and a connection member connecting the plurality of battery modules to each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/310,539, filed on Dec. 17, 2018, which is the National Phase under 35U.S.C. § 371 of International Application No. PCT/KR2018/000199, filedon Jan. 4, 2018, which claims priority under 35 U.S.C. § 119(a) toKorean Patent Application No. 10-2017-0036034, filed on Mar. 22, 2017 inthe Republic of Korea, all of which are hereby expressly incorporated byreference into the present application.

TECHNICAL FIELD

The present disclosure relates to a battery pack, and more particularly,to a battery pack capable of improving an energy density.

BACKGROUND ART

As technology development and demand for a mobile device have increased,demand for a secondary battery as an energy source has rapidlyincreased. Conventionally, a nickel-cadmium battery or a hydrogen ionbattery has been used as the secondary battery. However, a lithiumsecondary battery is recently widely used because charging anddischarging is free due to rare memory effect in comparison with anickel-based secondary battery, a self-discharge rate is very low, andan energy density is high.

The lithium secondary battery mainly uses a lithium oxide and acarbonaceous material as a positive electrode active material and anegative electrode active material, respectively. The lithium secondarybattery includes an electrode assembly in which a positive electrodeplate and a negative electrode plate, respectively coated with thepositive electrode active material and the negative electrode activematerial, are arranged with a separator therebetween, and an outermember, that is a battery case, which seals and receives the electrodeassembly together with an electrolyte solution.

The lithium secondary battery includes a positive electrode, a negativeelectrode, and a separator interposed therebetween and an electrolyte.Depending on which material is used for the positive electrode activematerial and the negative electrode active material, the lithiumsecondary battery is classified into a lithium ion battery (LIB) and apolymer lithium ion battery (PLIB). Generally, an electrode of thelithium secondary battery may be prepared by applying the positive ornegative electrode active material to a current collector made ofaluminum or copper sheet, mesh, film, foil, or the like and then dryingthe same.

Recently, as the demand of hybrid electric vehicle or electric vehicleis increasing, energy storage devices such as battery packs are usedmore and more in the vehicles. Accordingly, there is a need to develop abattery pack having a high energy density and disposed on an underfloorof a hybrid electric vehicle or an electric vehicle.

DISCLOSURE Technical Problem

The present disclosure is directed to providing a battery pack having arelatively high energy density by improving the space efficiency.

In addition, the present disclosure is directed to providing a batterypack that may be easily disposed on an underfloor of a hybrid electricvehicle or an electric vehicle.

Technical Solution

In one aspect of the present disclosure, there is provided a batterypack, comprising: a battery module having a plurality of stacked batterycells and a casing member surrounding the plurality of battery cells;and a connection member configured to connect the plurality of batterymodules to each other.

Also, the plurality of battery modules connected by the connectionmember may be arranged in a single layer.

In addition, the plurality of battery modules may be arranged to have atleast one column or at least one row.

Also, the casing member may include: an upper casing disposed at anupper portion of the battery cells; and side casings disposed at sidesurfaces of the battery cells and coupled to the upper casing, and anopening having a preset size may be formed in at least one of the sidecasings, and the connection member may be coupled to the opening of theside casing.

In addition, the connection member may include: a first insert insertedinto the opening of the side casing of any one battery module among theplurality of battery modules; and a second insert inserted into theopening of the side casing of another battery module among the pluralityof battery modules.

Also, the connection member may further include a stopper formed betweenthe first insert and the second insert to prevent the first insert andthe second insert from being inserted in excess of a predeterminedrange.

In addition, the stopper may extend from a portion between the firstinsert and the second insert toward a direction intersecting thedirection in which the first insert and the second insert are formed.

Also, the connection member may be fixed to the side casing by means ofa screwing structure or a hooking structure.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a vehicle, comprising the battery pack described above.

Advantageous Effects

According to the embodiments of the present disclosure, the battery packmay have a relatively high energy density by improving the spaceefficiency.

In addition, since a plurality of battery modules are arranged in asingle layer, the battery pack may be easily disposed on an underfloorof a hybrid electric vehicle or an electric vehicle.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view showing a battery pack accordingto the first embodiment of the present disclosure.

FIG. 2 is an exploded perspective view showing a battery module in thebattery pack according to the first embodiment of the presentdisclosure.

FIG. 3 is an exploded perspective view showing battery modules andconnection members in the battery pack according to the first embodimentof the present disclosure.

FIG. 4 is an enlarged perspective view showing a portion A of FIG. 3 .

FIG. 5 is a partial cross-sectioned view showing that the batterymodules are connected by the connection members in the battery packaccording to the first embodiment of the present disclosure.

FIG. 6 is a perspective view showing that the battery modules areconnected by the connection member in the battery pack according to thefirst embodiment of the present disclosure.

FIG. 7 is an exploded perspective view showing battery modules andconnection members in a battery pack according to the second embodimentof the present disclosure.

FIG. 8 is an enlarged perspective view showing a portion B of FIG. 7 .

FIG. 9 is a partial cross-sectioned view showing that the batterymodules are connected by the connection members in the battery packaccording to the second embodiment of the present disclosure.

FIG. 10 is an exploded perspective view showing battery modules andconnection members in a battery pack according to the third embodimentof the present disclosure.

FIG. 11 is an enlarged perspective view showing a portion C of FIG. 10 .

FIG. 12 is a partial cross-sectioned view showing that the batterymodules are connected by the connection members in the battery packaccording to the third embodiment of the present disclosure.

BEST MODE

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Priorto the description, it should be understood that the terms used in thespecification and the appended claims should not be construed as limitedto general and dictionary meanings, but interpreted based on themeanings and concepts corresponding to technical aspects of the presentdisclosure on the basis of the principle that the inventor is allowed todefine terms appropriately for the best explanation. Therefore, thedescription proposed herein is just a preferable example for the purposeof illustrations only, not intended to limit the scope of thedisclosure, so it should be understood that other equivalents andmodifications could be made thereto without departing from the scope ofthe disclosure.

In the drawings, the size of each element or a specific part of theelement may be exaggerated, omitted, or schematically illustrated forconvenience and clarity of a description. Thus, the size of each elementdoes not entirely reflect the actual size of the element. A detaileddescription of well-known functions or elements associated with thepresent disclosure will be omitted if it unnecessarily obscures thesubject matter of the present disclosure.

The term, ‘combine’ or ‘connect’ as used herein, may refer not only to acase where one member and another member are directly combined ordirectly connected but also a case where one member is indirectlycombined with another member via a connecting member or is indirectlyconnected.

FIG. 1 is a schematic perspective view showing a battery pack accordingto the first embodiment of the present disclosure, FIG. 2 is an explodedperspective view showing a battery module in the battery pack accordingto the first embodiment of the present disclosure, FIG. 3 is an explodedperspective view showing battery modules and connection members in thebattery pack according to the first embodiment of the presentdisclosure, FIG. 4 is an enlarged perspective view showing a portion Aof FIG. 3 , FIG. 5 is a partial cross-sectioned view showing that thebattery modules are connected by the connection members in the batterypack according to the first embodiment of the present disclosure, andFIG. 6 is a perspective view showing that the battery modules areconnected by the connection member in the battery pack according to thefirst embodiment of the present disclosure.

Referring to FIGS. 1 to 6 , a battery pack 10 according to the firstembodiment of the present disclosure includes a plurality of batterymodules 100 and a connection member 200. Referring to FIG. 1 , thebattery pack 10 may be configured so that a plurality of battery modules100 connected to each other are coupled to, for example, a plate 400.

Referring to FIG. 2 , the battery module 100 may include a plurality ofbattery cells 110 and a casing member 120.

The plurality of battery cells 110 may be stacked one another in variousways. For example, the battery cells 110 may be accommodated in acartridge assembly formed by injecting-molding plastic, and a pluralityof cartridge assemblies may be stacked one another. However, theplurality of battery cells 110 may be stacked in various ways withoutbeing limited to the above.

The casing member 120 may be configured to surround the plurality ofbattery cells 110. The casing member 120 may be configured in variousways, and, for example, may include an upper casing 121 disposed at anupper portion of the battery cells 110 and side casings 122 disposed atside portions of the battery cells 110 and coupled to the upper casing121. Here, the casings may be coupled to each other in various ways, forexample by screwing, welding, riveting, bolting, pin coupling,bracketing, moment bonding or the like. Referring to FIG. 2 , an opening126 having a preset size may be formed in the side casing 122, and aconnection member 200, explained later, may be coupled to the opening126 of the side casing 122 to connect a plurality of battery modules 100to each other. Meanwhile, a lower casing disposed at a lower portion ofthe battery cells 110 and coupled to the side casings 122 may be furtherprovided.

The connection member 200 is configured to connect the plurality ofbattery modules 100 to each other. Referring to FIGS. 3 to 5 , theconnection member 200 includes a first insert 210 inserted into theopening 126 formed in a side casing 122 a of any one battery module 100a among the plurality of battery modules 100 and a second insert 220inserted into the opening 126 formed in a side casing 122 c of anotherbattery module 100 b among the plurality of battery modules 100. Thefirst insert 210 may be inserted into the opening 126 formed in the sidecasing 122 a of any one battery module 100 a among the plurality ofbattery modules 100 and then coupled thereto by using a screw 300 or acoupling member using a bolt and a nut. Also, the second insert 220 maybe inserted into the opening 126 formed in the side casing 122 c ofanother battery module 100 b among the plurality of battery modules 100and then coupled thereto by using a screw 300 or a coupling member usinga bolt and a nut. Here, the opening 126 may be formed to correspond tothe length of the first insert 210 or the second insert 220, for exampleto have the same shape.

Referring to FIGS. 3 and 6 , the connection member 200 is respectivelyconnected to the side casings 122 a, 122 c of the plurality of batterymodules 100 a, 100 b to connect neighboring battery modules 100 a, 100 bto each other. By doing so, a frame or the like for supporting thebattery modules 100 is not necessary, and thus the battery pack may beassembled simply. Thus, the material cost and the processing cost arereduced, and the space occupied by the frame is unnecessary to allow thebattery modules 100 to be more closely adhered to each other. For thisreason, the battery pack 100 may have an improved energy density. Here,the side casing 122 not only protects the battery cells 110 but alsostructurally supports the battery module 100, and thus the side casing122 may have a thickness enough to have sufficient rigidity

The connection member 200 may be fixed and coupled to the side casing122 of the battery module 100 in various ways. For example, theconnection member 200 may be coupled by screws 300 or by bolts and nuts,or in a simple way using a hooking manner. Alternatively, the connectionmember 200 may be coupled to the side casing 122 by welding.

Referring to FIGS. 1 and 3 , after the plurality of battery modules 100are connected by the connection member 200, the plurality of batterymodules 100 may be arranged in a single layer, and the plurality ofbattery modules 100 may be arranged to have at least one row or at leastone column. If the plurality of battery modules 100 are arranged in asingle layer as above, the overall height of the battery modules 100 islower than the case where the battery modules 100 are arranged in aplurality of layers. Thus, the plurality of battery modules 100 may beeasily arranged in a space with a limited height such as an underfloorof an electric vehicle or the like.

Hereinafter, the operation and effect of the battery pack 10 accordingto the first embodiment of the present disclosure will be described.

Referring to FIG. 3 , the battery module 100 may include a side casing122 having an opening 126 formed therein, and the connection member 200is inserted into the openings formed in the side casings 122 a, 122 c ofthe battery modules 100 a, 100 b adjacent to each other among theplurality of battery modules 100 a and then coupled thereto by the screw300 or the like. Since the plurality of battery modules 100 a, 100 b areconnectable to each other without a frame as described above, morebattery modules 100 may be disposed in the space occupied by the frame,thereby improving the energy density.

FIG. 7 is an exploded perspective view showing battery modules andconnection members in a battery pack according to the second embodimentof the present disclosure, FIG. 8 is an enlarged perspective viewshowing a portion B of FIG. 7 , and FIG. 9 is a partial cross-sectionedview showing that the battery modules are connected by the connectionmembers in the battery pack according to the second embodiment of thepresent disclosure.

Hereinafter, the function and effect of a battery pack 10 according tothe second embodiment according to the present disclosure will bedescribed with reference to the drawings, but features common to thebattery pack 10 according to the first embodiment of the presentdisclosure will not be described again in detail.

The second embodiment of the present disclosure is different from thefirst embodiment in the point that a stopper 240 is formed at theconnection member 200.

Referring to FIGS. 7 and 8 , the stopper 240 may be formed between thefirst insert 210 and the second insert 220 to prevent the first insert210 and the second insert 220 from being inserted in excess of apredetermined range. In addition, a step (see a portion a in FIG. 8 )may be formed between one side casing 122 a and another side casing 122b disposed adjacent to the one side casing 122 a and contacting the oneside casing 122 a so that the stopper 240 may be placed thereon. Thatis, the stopper 240 may be placed on the step a formed between the sidecasings 122 a, 122 b which are in contact with each other. Accordingly,when the plurality of battery modules 100 are connected to each other bythe connection member 200, the plurality of battery modules 100 may becoupled not in a spaced state but in a contacting state (In FIG. 9 , theside casings 122 b, 122 d are in contact with each other) (see FIG. 9 ).

Referring to FIGS. 7 to 9 , the stopper 240 may extend in a directionintersecting the direction in which the first insert 210 and the secondinsert 220 are formed, for example in a direction perpendicular to thedirection in which the first insert 210 and the second insert 220 areformed. In addition, the stopper 240 may be formed to extend from aportion between the first insert 210 and the second insert 220, forexample from a middle portion 230 (see FIG. 4 ) of the first insert 210and the second insert 220. However, the extending direction and theextending position of the stopper 240 may be set in various ways.

FIG. 10 is an exploded perspective view showing battery modules andconnection members in a battery pack according to the third embodimentof the present disclosure, FIG. 11 is an enlarged perspective viewshowing a portion C of FIG. 10 , and FIG. 12 is a partialcross-sectioned view showing that the battery modules are connected bythe connection members in the battery pack according to the thirdembodiment of the present disclosure.

Hereinafter, the function and effect of a battery pack 10 according tothe third embodiment according to the present disclosure will bedescribed with reference to the drawings, but features common to thebattery pack 10 according to the first or second embodiment of thepresent disclosure will not be described again in detail.

The third embodiment of the present disclosure is different from thesecond embodiment in the point that battery modules 100 adjacent to eachother are spaced apart from each other by the stopper 240 formed at theconnection member 200.

Referring to FIGS. 10 to 12 , the stopper 240 of the third embodiment isidentical to that of the second embodiment, but in the third embodiment,a step is not formed between one side casing 122 a and another sidecasing 122 b disposed adjacent to the one side casing 122 a andcontacting the one side casing 122 a so that the stopper 240 may beplaced thereon (see a portion b in FIG. 11 ), different from the secondembodiment. Thus, if the connection member 200 is coupled to theplurality of battery modules 100, battery modules 100 adjacent to eachother are spaced apart from each other. In other words, a predeterminedgap x (see FIG. 12 ) of a predetermined interval is present between thebattery modules 100 connected to each other. Air may move through thespaced gap x between the battery modules 100 to cool the battery modules100. In other words, the space formed by the gap x between the batterymodules 100 is used for heat dissipation of the battery modules 100.

Meanwhile, a vehicle (not shown) according to an embodiment of thepresent disclosure may include the battery pack 10 described above. Thebattery pack 10 may be used for various machines or devices usingelectricity and may be, for example, disposed in an electric vehicle,particularly on an underfloor of the electric vehicle. Here, theelectric vehicle may include not only an electric vehicle driven purelyby electricity but also a hybrid electric vehicle using another kind ofenergy together with electric energy.

The present disclosure has been described in detail. However, it shouldbe understood that the detailed description and specific examples, whileindicating preferred embodiments of the disclosure, are given by way ofillustration only, since various changes and modifications within thescope of the disclosure will become apparent to those skilled in the artfrom this

DETAILED DESCRIPTION Industrial Applicability

The present disclosure is directed to a battery pack and is particularlyapplicable to industries associated with a secondary battery.

What is claimed is:
 1. A battery module comprising: a plurality of stacked battery cells; and a casing member surrounding the plurality of battery cells, the casing member comprising: an upper casing covering an upper portion of the plurality of battery cells; a pair of first side casings located at opposite sides of the plurality of battery cells, each of the first side casings having an angle iron shape; and a pair of second side casings located at opposite sides of the plurality of battery cells different from the opposite sides where the pair of first side casings are located, each of the second side casings having a constant overall width, and at least one opening extending in a longitudinal direction from an end of the of the second side casing, the opening being a blind hole.
 2. The battery module according to claim 1, wherein opposite ends of the pair of first side casings are aligned with opposite ends of the pair of side casings to be flush with each other.
 3. The battery module according to claim 1, wherein opposite ends of the pair of first sides casings are offset with respect to opposite ends of the pair of second side casings to define stepped portions between adjacent first side casings and second side casings.
 4. A battery pack comprising: a plurality of battery modules, each battery module comprising: a plurality of stacked battery cells; and a casing member surrounding the plurality of battery cells, the casing member comprising: an upper casing covering an upper portion of the plurality of battery cells; a pair of first side casings located at opposite sides of the plurality of battery cells, each of the first side casings having an angle iron shape; and a pair of second side casings located at opposite sides of the plurality of battery cells different from the opposite sides where the pair of first side casings are located, each of the second side casings having a constant overall width, and at least one opening extending in a longitudinal direction from an end of the of the second side casing, the opening being a blind hole; a connection member connecting adjacent battery modules to each other, the connection member being inserted into the openings of two adjacent battery modules of the plurality of battery modules such that the upper casings of the plurality of battery modules are coplanar.
 5. The battery pack according to claim 4, wherein, for each battery module, opposite ends of the pair of first side casings are aligned with opposite ends of the pair of side casings to be flush with each other.
 6. The battery pack according to claim 5, wherein the connection member is substantially entirely enclosed by the openings of the two adjacent battery modules such that opposites ends of the connector are not exposed to an exterior of the battery pack.
 7. The battery pack according to claim 6, wherein the connection member includes a stopper, the stopper being larger than the openings of the two adjacent battery modules such that the stopper is located outside the openings of the two adjacent battery modules.
 8. The battery pack according to claim 7, wherein the connection member includes: a first insert inserted into the opening of the second side casing of one of the two adjacent battery modules; and a second insert inserted into the opening of the second side casing of another to the two adjacent battery modules.
 9. The battery pack according to claim 8, wherein the stopper is formed between the first insert and the second insert to prevent the first insert and the second insert from being inserted in excess of a predetermined range.
 10. The battery pack according to claim 9, wherein the stopper extends from a portion between the first insert and the second insert toward a direction intersecting the direction in which the first insert and the second insert are formed.
 11. The battery pack according to claim 4, wherein, for each battery module, opposite ends of the pair of first sides casings are offset with respect to opposite ends of the pair of second side casings to define stepped portions between adjacent first side casings and second side casings.
 12. The battery pack according to claim 11, wherein the connection member is substantially entirely enclosed by the openings of the two adjacent battery modules such that opposites ends of the connector are not exposed to an exterior of the battery pack.
 13. The battery pack according to claim 12, wherein the connection member includes a stopper, the stopper being larger than the openings of the two adjacent battery modules such that the stopper is located outside the openings of the two adjacent battery modules, the stopper being seated in adjacent stepped portions of the two adjacent battery modules.
 14. The battery pack according to claim 13, wherein the connection member includes: a first insert inserted into the opening of the second side casing of one of the two adjacent battery modules; and a second insert inserted into the opening of the second side casing of another to the two adjacent battery modules.
 15. The battery pack according to claim 14, wherein the stopper is formed between the first insert and the second insert to prevent the first insert and the second insert from being inserted in excess of a predetermined range.
 16. The battery pack according to claim 15, wherein the stopper extends from a portion between the first insert and the second insert toward a direction intersecting the direction in which the first insert and the second insert are formed.
 17. The battery pack according to claim 4, wherein the connection member is fixed to the side casings by means of a screw or bolt distinct from the connection member. 